Thread: last coat of varnish..........

Learning how to "flow" on varnish is a bit of an art now. There aren't many that know what I'm talking about and those that do, know how long it took before they figured it out.

In short, you have to learn what the "mix will be for the day (each is different) and thin as needed. Penetrol is fine, but 10% is pushing it on the last coats (it can screw with the shine). As a rule, the last coats should be quite thin coatings, compared to the "bulking" coats preformed early in the process.

What would you use to thin it down?
It is shiny as but as I said I can see brush marks. I tried to thin it in one coat with mineral turps and found it bubbled a fair bit.
My plan is to sand it flat again with 360 wet and try a different brush. The brush I'm using is brand new and wasn't cheap but I found a softer one in my paint department.

Reiner

Reiner,
Bubbles in brightwork are the result of too quick a drying (the varnish boils) or shaking the can ( a no-no).
Use a two inch brush for the small dinghy, varnish early in the morning, just after sunrise is a good time and the wind has not yet come up. Make sure that you use a tack cloth on the final coats. If you are right handed, lay from the left to the right, doing sections no more than 18 inches wide. Lay off lightly with the brush laying flat in the hand and with very light pressure, but do NOT play with it. It will only be two maybe three brushes across the paint to smooth it out.

As PAR says, every day is different, and getting the mix right sometimes does not worj until you have just about finished anyhow, so don't loose too much sleep over it.

I was the Shipwright for the Australian National Museum before I went cruising, and did all their brightwork, so have had plenty of practice. Someone stole all my sable brushes whilst I was there, so only have the badgers left, but even the cheap (thicker ones) of the Chinese white bristles can do very good work when you have played enough with them.

Thank you for that landlubber. I will try a different brush as well. Your technic makes a lot of sense. What can I use to thin the paint down? and if you can't stir it how do you mix the thinner in? It is raining again this morning so there will be no final coat today but plenty of time for sanding.

Thinning the varnish depends of course on what sort it is. Generally today varnish is not varnish at all, it is single pack polyurethane.

The can will have on it what to use for thinning, do not use too much, but it will most likely be required.

Bubbles can be caused a by a few different things. One of the more common mistakes a novice makes is two fold with the brush. The first is brushing too quickly. It's not paint and needs to literally flow, from the brush to the work, not smashed into the surface like is done with paint. Use deliberate and slow strokes. At first the right speed will seem too slow, but it's not and you'll get use to it. The second thing when brushing is not to over work the material. Varnish doesn't like to to be smeared around. Use just enough strokes to lay down a smooth, clean, uniform coating, then move to the next area. Additional strokes will do nothing but increase the possibility of brush marks.

I use a three step method to apply varnish. The first coats are purely to bulk out the coating, so there's enough room to flatten it good and smooth. This usually requires at least 6 moderately heavy coats. The last is knocked down with paper and the smoothing coats go down. These also are moderately thick, but about 50% of each coat is block sanded away to really smooth the surface. The last few may be wet sanded. In both of these stages, I'm not worried about brush marks as they get sanded out. The final stage I like to spray, which solves a lot of problems. I just thin the mixture until I don't have stipple. If it's brushed, it also needs to be thinned (mineral spirits) which lets it lay down (self level) and flatten out the brush marks. Getting the right percentage of thinner to varnish is literally a crap shoot, until you get a feel for the materials. I usually try to sneak up on it by adding thinner as I go.

If you are working with a polyurethane then the same applies, but you have to work faster and be more deliberate about your actions. This stuff will literally dry as you're applying it, so you can't screw around.

The traditional varnishers like the old Lubber there are going to scream, but I've found that foam brushes lay down a better flow then a regular brush, even the good ones. They don't hold as much material and they can drip, but they do leave much less brush marks and generally produce a better finish. You have to be careful about their limitations, but they can make a novice look good.

Thank you Par, great advice. I looked at the foam brushes yesterday but didn't think they would work on varnish. The rain has stopped and I block sanded yesterday. If it stays dry I have another go with my new brush. If that doesnt work I get the gun out and spray it on. I was thinking that earlier but everybody was saying you have to use the brush. The other option I was thinking of was to block sanded and go trough to maybe 800 grid and polish it after. I don;t know if you can do that with varnish but it was on my list of tries.
Thanks again to everybody, a greatful beginner will keep at it
Cheers
Reiner

Be very careful about using too fine a grit of paper. You need some "tooth" for the next coat to grab. 800 is way too fine. You can't see scratches left with 320, so don't bother going higher.

Yes, varnish can be buffed, which will remove minor blemishes, light scratches, bugs legs, etc., but it's still just polishing, the brush marks are much deeper then anything you can buff out, unless you spend hours at it. It's not easy to do, as you can burn the varnish easily. The varnish has to be really cured too, which is usually about a month.

Go out and get a couple of foam brushes. Apply a thin coat in long, slow, smooth, uniform strokes and see how it works for you. The worst you'll have to do is wet sand through this coat and try again. I think you'll be surprised with the foam. Go slow, oh and one more thing, did I mention use slow brush strokes?

Thanks to all your good advise today I put on my best coat of varnish. Fantastic.
I did use a brush because I bought that yesterday and wasn't going to buy a foam before trying the brush. It looks pretty good and I will post some photos as soon as I know how.
The varnish by the way is from International and it's called "Schooner Tropical" I was told that is the stuff to use up here in Queensland.
Tomorrow I coat the seats one more time and thats it. The side decks and frint and rear are done. I don't think I can do any better that that.
I do realise I did never put on enough varnish before per coat and I di fold the brush over . Thanks againb guys.
One last question how do I mantain the surface in years to come......I hope I don't have to do this every year.

cheers
Reiner

I don't want to tell him. Someone else can give you the news.

PAR, what a chicken....I am, used to being abused on the net so another one won't hurt.

YES you do have to do it, but not every year if it is outside, it will be every six months maximum.

If the boat is stored in a shed, then cover it up away from light as much as possible, but do NOT use a plastic tarp as it will induce heat and trap moisture and guess who feeds on that...yep Mr. Rot.

Brightwork on moored yachts in Queensland and any high sub tropical to tropical region should be recoated every three months with a light sand down and a gloss finish applied.
What I used to do on my yacht was section the areas to be done so that it is not a major job. I do the toe rails one day, the cabin sides one day, the coamings one day, soo that results in a nice finish all year round, without having to do a big job every year. You can get to six months usually quite ok, BUT, if the finish has even the slightest crack or easy spot (places where not much finish is applied, such as sharp edges) then the result will be exposed wood and you will have to do the job properly to fix it, so the best thing to do is a quicky every three months for outside exposed wood.

Cairns (NQ) will be three months if you are lucky. High rain areas are very prone to problems.

Just as well we like what we do eh.....

Yep, clear finishes on wood are the most difficult results to live with, exposed to the elements. I'm in a sub tropical climate (this is the first full day of spring here and it was over 26c and sunny) and "bright" work is preformed every few months.

On the other hand, if you can limit UV exposure, you can have great durability from these clear coatings. I have a varnish job (boat) that is 20 years old and just now needs to be redone for the first time. It's also stored indoors and under cover so zero sun light can get at it, including reflected light. It's also kept clean and dry.

The biggest mistake the novice makes is to let the varnish "get away from you", which means the surface gets damaged and must be renewed, rather then maintained or repaired. Most clear coatings can be touched up, if you get to it soon enough. If you let it go too long, you'll have to strip the whole thing down and start over. This is especially true of polyurethane finishes, which need a close eye on them. They are more durable then oil based varnishes, but are much less tolerant of neglect, before you can no longer repair it.

Thanks Landlubber and Par for trying to be gentle. My boat is only 16 ft and sits in a carport but after reading what you said it will get a cover. I will try to find a canvas cover soft and big enough. No wonder people paint all the boats in colours but I'm glad mine is all timber except the hull which is yellow. I will keep an eye on mine and see how ofther I have to do it. Do you pull all the hardware off when you recoat? and how do I know when it needs doing?
Since it is under cover I was hoping one coat every six month? It would be nice if it could be every 12 month. We do a lot of camping, we do some fishing, I ride a dirt bike, We have two kayaks and a couple of VW's....... plus 1 acre garden here at home and a property 3 acres with rainforestand 40min from here.......our house needs work All the stuff needs attention and I do love doing nothing sometimes too.
All good....... we just have to sleep less.....hehehe
Thanks again
Cheers
Reiner

What are member's experience with using sprayers for paint, particularly for the last 1 or 2 coats?
I used Exterior water based Acrylic in an electric spray gun for my last hull paint, and it worked a treat.
Why is everyone still using oil based finishes? No one uses them for the outside of houses anymore, why for boats?